Northern Virginia's two freshman Republican congressmen have far outstripped their Democratic challengers in fund-raising, putting the Democrats at a significant disadvantage in their ability to pay for television advertising during the crucial last three weeks of the campaigns.

The state's Republican candidate for the U.S. Senate, Paul S. Trible Jr., also has overwhelmed his Democratic opponent in fund-raising, according to Federal Election Commission finance statements filed yesterday. Trible had raised $1.7 million as of Oct. 1, compared to $622,000 for Lt. Gov. Richard J. Davis, the Democratic candidate.

Rep. Stanford E. Parris of the 8th District, which includes Alexandria, southern Fairfax and parts of Stafford and Prince William counties, reported yesterday he had raised $539,000, the most of any congressional candidate in the Washington area and more than double the $248,000 total of his Democratic opponent, former representative Herbert E. Harris II. Rep. Frank R. Wolf, whose 10th District includes Arlington, northern Fairfax and Loudoun counties, reported contributions of nearly $349,000, compared to $240,000 for his opponent, Ira M. Lechner.

Harris, who is locked in a tight race with Parris as they face each other for the third time, acknowledged yesterday he is unlikely to raise the $400,000 he originally projected. Lechner's campaign manager, Donald S. Beyer Jr., said yesterday that, unless the campaign can raise $30,000 by Monday, Lechner will probably cancel plans to advertise on television.

Parris said he had received money from more than 6,000 people, which his campaign claims is a record for Virginia congressional races, and he released the names of small contributors, as did Wolf, in what their staffs said was an attempt to prove they are not candidates of the rich.

Campaign officials for challengers Harris and Lechner said yesterday they were pleased by their fund-raising totals.

"We have been outspent 2 to 1 in every election . . . . There's nothing that we want to do that we're not doing," said Harris aide Peter Intermaggio.

"I think it's wonderful," said Beyer, adding that as of yesterday Lechner had raised $275,000, which exceeds by $5,000 the total amount former Rep. Joseph L. Fisher collected in his unsuccessful 1980 race against Wolf. "Money is still coming in consistently and we're very optimistic. We've known all along we can't compete against Congressman Wolf on television, but we'd like to make a presence."

All three Republicans have been given money by state and national party committees, which will vastly outspend their Democratic counterparts. Together Wolf and Parris have received more than $40,000 in cash from GOP affiliates, while Lechner and Harris have received less than $7,000.

Trible's total includes $291,000 from the Republican Senatorial Campaign Committee. Trible's campaign manager, Judy Peachee, said the candidate hopes to raise more than $2 million and will spend between $300,000 and $500,000 on radio and television commercials between now and Nov. 2.

Among Parris' most loyal supporters are influential lawyer-developer John T. (Til) Hazel Jr. and his family, who have given at least $11,000 to the campaign. Hazel's partners and staff have given an additional $6,000, according to the reports. "The truth of the matter is, Stan Parris is probably as close a friend as I have got," Hazel said. "We go hunting together, we swap stories . . . . We are all very fond of Stan."

Parris has raised $193,000, or about 36 percent of his total funds, from corporate political action committees (PACs), ranging from the National Rifle Association ($4,950) to Reader's Digest ($500). Wolf has raised about

45,000 from PACs--about 41 percent of his total -- including $10,000 from the American Medical Association and $1,000 from New Right strategist Paul Weyrich's Washington-based Committee for the Survival of a Free Congress.

A larger proportion of contributions reported by the Democratic challengers comes from PACs, most of them affiliated with labor unions. They include the American Federation of Government Employees and the National Education Association. Harris reports that 48 percent, or $120,000, of his contributions are from PACs, while an estimated 45 percent, or $106,000, of Lechner's total is PAC money.

Also contributing to this article was Washington Post staff writer Michael Isikoff.